A Fourier-Laplace transform finite element method (FLTFEM) for the analysis of contaminant transport in porous media

In many practical situations, a simplified two-dimensional model is often s ufficiently accurate for practical purposes, however on some occasions it i s still necessary to consider the full three-dimensional situation. Convent ional numerical techniques such as the finite difference and finite element methods are able to deal with contaminant transport under 3D conditions, h owever the computational effort involved in using them is often very large. Under some circumstances it is possible to perform 3D analyses more effici ently. A particular case is when the geometry is 2D but the problem is actu ally 3D. In such cases the analysis can be simplified by application of a F ourier transform. In this paper, the dimensions of the contaminant transport problem will be reduced by one and the transient mass transport equation will be transforme d into a time-independent mass transport equation through the use of a comb ination of integral transforms (Laplace and Fourier transforms) and a finit e element technique. The mathematical model developed here is called Fourie r-Laplace transform finite element method (FLTFEM). By using the FLTFEM a t hree-dimensional transient problem can be analysed as a two-dimensional tim e-independent problem and the computational cost will thus greatly be reduc ed. Copyright (C) 1999 John Wiley & Sons, Ltd.